BIO 360 - Exam 1 - Chapter 3 Review Questions

Question 1

List the four general functions of the cell membrane.

Answer 1

(1) barrier between cell and ECF
(2) regulate exchange of material between cell and ECF
(3) transfer information between the cell and other cells
(4) provide structural support

Question 2

In 1972, Singer and Nicolson proposed the fluid mosaic model of the cell membrane. According to this model, the membrane is composed of a bilayer of ______ and a variety of embedded ______, with ______on the extracellular surface.

Answer 2

phospholipids; proteins; carbohydrates

Question 3

What are the two primary types of biomolecules found in the cell membrane?

Answer 3

phospholipids and proteins

Question 4

Define and distinguish between inclusions and organelles. Give an example of each.

Answer 4

Inclusions: particles of insoluble material.
* glycogen and ribosomes
Organelles: are separated from cytosol by membranes.
* mitochondria and Golgi apparatus

Question 5

Define cytoskeleton. List five functions of the cytoskeleton.

Answer 5

A network of interlinking protein filaments present in the cytoplasm of all cells.
A flexible, changeable, three-dimensional scaffold of actin, microfilaments, intermediate filaments, and microtubules.

Functions:
(1) mechanical strength
(2) stabilize position of organelles
(3) transport material
(4) link cells together
(5) movement

Question 6

Match each term with the description that fits it best:

a. cilia
b. centriole
c. flagelo­lum
d. centro­some

1. in human cells, appears as single, long, whiplike tail
2. short, hairlike structures that beat to produce currents in fluids
3. a bundle of microtubules that aid in mitosis
4. the microtubule-organizing center

Answer 6

(a) 2, (b) 3, (c) 1, (d) 4

(a) cilia: short, hairlike structures that beat to produce currents in fluids.

(b) centriole: a bundle of microtubules that aid in mitosis.

(c) flagelo­lum: in human cells, appears as single, long, whiplike tail.

(d) centro­some: the microtubule-organizing center

Question 7

Exocrine glands produce watery secretions (such as tears or sweat) called ______secretions, or stickier solutions called ______secretions.

Answer 7

serous; mucous

Question 8

Match each organelle with its function:

a. endoplasmic reticulum
b. Golgi apparatus
c. lysosome
d. mitochono­drion
e. peroxo­isome

1. powerhouse of the cell where most ATP is produced
2. degrades long-chain fatty acids and toxic foreign molecules
3. network of membranous tubules that synthesize biomolecules
4. digestive system of cell, degrading or recycling components
5. modifies and packages proteins into vesicles

Answer 8

(a) 3, (b) 5, (c) 4, (d) 1, (e) 2

(a) endoplasmic reticulum: network of membranous tubules that synthesize biomolecules.

(b) Golgi apparatus: modifies and packages proteins into vesicles.

(c) lysosome: digestive system of cell, degrading or recycling components.

(d) mitochono­drion: powerhouse of the cell where most ATP is produced.

(e) peroxo­isome: degrades long-chain fatty acids and toxic foreign molecules.

Question 9

What process activates the enzymes inside lysosomes?

Answer 9

very acidic conditions

Question 10

______ glands release hormones, which enter the blood and regulate the activities of organs or systems.

Answer 10

endocrine

Question 11

List the four major tissue types. Give an example and location of each.

Answer 11

(1) connective tissue (tendons that hold muscles to bones)
(2) epithelium (skin)
(3) neural tissue (the brain)
(4) muscular tissue (heart and skeletal muscles)

Question 12

The largest and heaviest organ in the body is the ______.

Answer 12

skin

Question 13

Match each protein to its function. Functions in the list may be used more than once.

a. cadherin
b. CAM
c. collagen
d. connexin
e. elastin
f. fibrillin
g. fibronectin
h. integrin
i. occludin

1. membrane protein used to form cell junctions
2. matrix glycoprotein used to anchor cells
3. protein found in gap junctions
4. matrix protein found in connective tissue

Answer 13

(a) 1, (b) 1, (c) 4, (d) 3, (e) 4, (f) 4, (g) 4, (h) 1, (i) 1

(a) cadherin: membrane protein used to form cell junctions.
(b) CAM: membrane protein used to form cell junctions.
(h) integrin: membrane protein used to form cell junctions.
(i) occludin: membrane protein used to form cell junctions.

(c) collagen: matrix protein found in connective tissue.
(e) elastin: matrix protein found in connective tissue.
(f) fibrillin: matrix protein found in connective tissue.
(g) fibronectin: matrix protein found in connective tissue.

(d) connexin: protein found in gap junctions.

Question 14

What three types of glands can be found within the skin? Name the secretion of each type.

Answer 14

• apocrine glands—waxy or milky secretions
• sebaceous glands—a mixture of lipids
• sweat glands—sweat

Question 15

The term matrix can be used in reference to an organelle or to tissues. What is the difference between mitochondrial matrix and tissue matrix?

Answer 15

• mitochondrial matrix—the internal compartment.
• tissue matrix—noncellular material found outside cells.

Question 16

List, compare, and contrast the three types of cell junctions and their sub-types. Give an example of where each type can be found in the body and describe its function in that location.

Answer 16

(1) Anchoring junctions (skin)—allow twisting and stretching of tissue.
(2) Tight junctions (epithelia)—prevent movement of materials between cells.
(3) Gap junctions (some muscles)—allow material to pass directly from cytoplasm of one cell to another.

Question 17

Which would have more rough endoplasmic reticulum: pancreatic cells that manufacture the protein hormone insulin, or adrenal cortex cells that synthesize the steroid hormone cortisol?

Answer 17

RER is where proteins are made, so pancreatic cells would have more.

Question 18

Define vesicle and describe at least three examples.

Answer 18

Vesicles—membranous spheres.
Examples: lysosomes, peroxisomes, secretory vesicles.

Question 19

Explain why a stratified epithelium offers more protection than a simple epithelium.

Answer 19

Stratified has many cell layers for protection; simple epithelium has only one layer.

Question 20

Transform this list of terms into a map of cell structure. Add functions where appropriate.

actin
cell membrane
actin
cell membrane
centriole
cilia
cytoplasm
cytoskeleton
cytosol
extracellular matrix
flagella
Golgi apparatus
intermediate
keratin
lysosome
microfilament
microtubule
mitochondria
nonmembranous organelle
nucleus
organelle
peroxisome
ribosome
rough ER
secretory vesicle
smooth ER
storage vesicle
tubulin

Answer 20

Map: See Fig. 3.2.

Question 21

Sketch a short series of columnar epithelial cells. Label the apical and basolateral borders of the cells.

Briefly explain the two different kinds of junctions found on these cells.

Answer 21

See Fig. 3.10e.
* Tight junctions prevent movement of material between cells.
* Leaky junctions allow some material to pass between cells.

Question 22

Arrange the following compartments in the order a glucose molecule entering the body at the intestine would encounter them: interstitial fluid, plasma, intracellular fluid. Which of these fluid compartments is/are considered extracellular fluid(s)?

Answer 22

(1) intracellular fluid
(2) interstitial fluid
(3) plasma

Interstitial fluid and plasma are ECF.

Question 23

Explain how inserting cholesterol into the phospholipid bilayer of the cell membrane decreases membrane permeability.

Answer 23

Cholesterol molecules fill space between phospholipid tails.

Question 24

Compare and contrast the structure, locations, and functions of bone and cartilage.

Answer 24

(1) bone is rigid due to calcification
(2) cartilage is firm but elastic
(3) bones are the primary support structure for the body
(4) cartilage forms the ear, nose, larynx, and spine
(5) cartilage helps hold bones together at the joints

Question 25

Differentiate between the terms in each set below:
a. lumen and wall
b. cytoplasm and cytosol
c. myosin and keratin

Answer 25

(a) lumen—hollow inside of an organ or tube.
(a) wall—cell layer.

(b) cytoplasm—everything inside the cell except the nucleus. (b) cytosol—semi-gelatinous, intracellular fluid.

(c) myosin—motor protein filament.
(c) keratin—structural protein fiber.

Question 26

When a tadpole turns into a frog, its tail shrinks and is reabsorbed. Is this an example of necrosis or apoptosis? Defend your answer.

Answer 26

Apoptosis—it is a normal part of development.

Question 27

In some instances, the extracellular matrix can be quite rigid. How might developing and expanding tissues cope with a rigid matrix to make space for themselves?

Answer 27

The matrix can be broken down, then reassembled.

Question 28

One result of cigarette smoking is paralysis of the cilia that line the respiratory passageways. What function do these cilia serve? Based on what you have read in this chapter, why is it harmful when they no longer beat? What health problems would you expect to arise? How does this explain the hacking cough common among smokers?

Answer 28

Cilia sweep mucus and particles up and out of the airways. When they fail, inhaled pathogens are more likely to reach the lungs, resulting in infections, inflammation, or cancer. The smoker’s cough removes the mucus that would normally be swept away by the cilia.

Question 29

Cancer is abnormal, uncontrolled cell division. What property of epithelial tissues might (and does) make them more prone to developing cancer?

Answer 29

Many epithelia are vulnerable to damage and need to be replaced frequently. Cells undergoing frequent mitosis are more likely to develop abnormal cell division.

Question 30

What might happen to normal physiological function if matrix metalloproteinases are inhibited by drugs?

Answer 30

MMPs are enzymes that dissolve the extracellular matrix, so blocking them might inhibit tissue growth and repair.